Utils/readme.md

# Utils

The utils only use standard JavaScript, so they can be used in Browser and NodeJS.

Also they are very small. Uncompressed and unminified only 3kb.

The utils have TypeScript definitions and are compatible with ES2015. 

## Lock

Lock is a very simple promise based Locking mechanism for JavaScript.

Usage:
``` typescript
    import { Lock } from "@hibas123/utils";

    const lock = new Lock();

    async doThingThatNeedsLocking() {
        let release = await lock.getLock(); // This will wait till lock from others is released

        // Do stuff that requires lock

        release(); // Release lock
    }
```

## Observable

Very simple and light weight Observable.

Usage:
``` typescript
    import { Observable } from "@hibas123/util";

    const server = new Observable(); // Get new Observable Server

    // Server can send and subscribe to messages
    // The publicAPI will only make the receiving parts available
    const public = server.getPublicApi();

    const func = (data)=>{
        console.log(data);
    }

    // func will be callen when a message is available
    let unsubscribe = public.subscribe(func);

    server.send("Hello World");

    // Unsubscribe using the returned function from subscribe
    unsubscribe();

    // OR

    // This will unsubscribe the function. Please note, that it can
    // only unsubscribe the exact function, that is used in subscribe
    public.unsubscribe(func);

    // This now won't call func anymore
    server.send("Hello World2");
```

## AwaitStore

This component can be used to await a specific value or to act as an variable with events.

Usage:
``` typescript
    import { AwaitStore } from "@hibas123/util";

    const server = new AwaitStore<number>(0); // Set initial value

    // Server can send and subscribe to messages
    // Only receiving is possible using the public API
    const public = server.getPublicApi();

    const func = (data)=>{
        console.log(data);
    }
    
    // awaitValue will also return a .ignore() function, that can be used to abort the promise completely
    public.awaitValue(5).then(()=>console.log("Got 5"));

    // func will be callen when a message is available and once with the current value
    // This will call func with the current value (0) and on every change after.
    public.subscribe(func);

    // This send will trigger the subscribtion func and also release the awaitValue causing "Got 5"
    // to appear in the console
    server.send(5);

    // This will unsubscribe the function. Please note, that it can
    // only unsubscribe the exact function, that is used in subscribe
    public.unsubscribe(func);

    // This now won't call func anymore
    server.send(8);
```


## License

MIT

Copyright (c) 2019 Fabian Stamm

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.